"It's an incredibly sad night for the Pollard family, for the Fire Department family, and for our city," Nigro said. "He lost his life tonight in the process of helping others."

Ladder Company 170 was called to the two-car accident on an elevated section of the highway that crosses the Mill Basin around 10 p.m., when in an attempt to reach the victims, Pollard slipped through a gap in the roadway and fell about 52 feet to the hard sand below.

"The members of 170 had responded in the opposite direction, on the eastbound side, and needed to cross over the roadway to assist the injured motorists," Nigro said. "And in the process of crossing over, Steven fell to the ground below."

He had apparently crossed the Jersey barrier not knowing there was a roughly 3-foot gap between the east and westbound lanes. He was pronounced dead at Kings County Hospital.

WATCH: FDNY procession honors firefighter Steven Pollard

Pollard comes from a family of firefighters. His father, Ray Sr., served 31 years in Brooklyn. His brother, Ray Jr., served 11 years in Brooklyn.

"This is a family who has done so much for New York City and now they're going through this loss and this pain," de Blasio said. "It's a very, very tough situation."

Pollard is the 1,151st member of the FDNY to die in the line of duty.

Uniformed Firefighters Association President Gerard Fitzgerald issued the following statement:

"In his short amount of time on the job, Steven Pollard made a massive impact in the Brooklyn community and was very well liked by his officers and fellow firefighters for his excellent work. Steven came from a line of firefighters who -- time and time again -- put their lives on the line to protect all New Yorkers, and on behalf of all UFA members, we want to extend our deepest sympathies to Steven's family, friends, and his fellow firefighters at Engine 257, Ladder 170 and Battalion 58. Steven truly epitomized what it means to be one of 'New York's Bravest,' and will be dearly missed."

Travis Simms, a city corrections officer, is the man Pollard and his fellow firefighters were rescuing as he was trapped in his SUV after a rollover on the Belt Parkway.

"He risked his life in order to save mine," said Simms.

As the rescuers jumped the center median to come to his aid, Pollard lost his footing, slipped through the void in the bridge and tumbled to his death.

He had just emerged from probation after a year on the job and at the Canarsie firehouse, colleagues remembered a man destined for greatness.

"He was a good firefighter," said Captain Jimmy Quinn of FDNY Ladder 170. "He was on his way to being a great firefighter. He was gonna be an anchor in the firehouse."

"He's definitely my hero, you know, definitely have to say a final goodbye," said Simms. "Hopefully I can say something to the family. And may he rest in peace."

Pollard and Simms were not strangers to each other. Before one became a firefighter and the other a correction officer, both worked together on the tarmac at Kennedy Airport for JetBlue Airways. Simms recognized Pollard from his picture after the accident, and realized he knew him.

He plans to attend the funeral so he can thank the Pollard family and the entire FDNY.